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bcachefs: bch2_accounting_mem_gc()

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Add a new helper to free zeroed out accounting entries, and use it in
bch2_replicas_gc2(); bch2_replicas_gc2() was killing superblock replicas
entries if their corresponding accounting counters were nonzero, but
that's incorrect - the superblock replicas entry needs to exist if the
accounting entry exists, not if it's nonzero, because we check and
create the replicas entry when creating the new accounting entry - we
don't know when it's becoming nonzero.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
This commit is contained in:
Kent Overstreet 2024-06-06 13:48:54 -04:00
parent 2574e95a8b
commit f73e6bb6d6
3 changed files with 42 additions and 6 deletions
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32
fs/bcachefs/disk_accounting.c
View File

@ -273,6 +273,38 @@ int bch2_accounting_mem_insert(struct bch_fs *c, struct bkey_s_c_accounting a, b
return ret;
}
static bool accounting_mem_entry_is_zero(struct accounting_mem_entry *e)
{
for (unsigned i = 0; i < e->nr_counters; i++)
if (percpu_u64_get(e->v[0] + i) ||
(e->v[1] &&
percpu_u64_get(e->v[1] + i)))
return false;
return true;
}
void bch2_accounting_mem_gc(struct bch_fs *c)
{
struct bch_accounting_mem *acc = &c->accounting;
percpu_down_write(&c->mark_lock);
struct accounting_mem_entry *dst = acc->k.data;
darray_for_each(acc->k, src) {
if (accounting_mem_entry_is_zero(src)) {
free_percpu(src->v[0]);
free_percpu(src->v[1]);
} else {
*dst++ = *src;
}
}
acc->k.nr = dst - acc->k.data;
eytzinger0_sort(acc->k.data, acc->k.nr, sizeof(acc->k.data[0]),
accounting_pos_cmp, NULL);
percpu_up_write(&c->mark_lock);
}
/*
* Read out accounting keys for replicas entries, as an array of
* bch_replicas_usage entries.

1
fs/bcachefs/disk_accounting.h
View File

@ -105,6 +105,7 @@ static inline int accounting_pos_cmp(const void *_l, const void *_r)
}
int bch2_accounting_mem_insert(struct bch_fs *, struct bkey_s_c_accounting, bool);
void bch2_accounting_mem_gc(struct bch_fs *);
static inline int __bch2_accounting_mem_mod(struct bch_fs *c, struct bkey_s_c_accounting a, bool gc)
{

15
fs/bcachefs/replicas.c
View File

@ -420,10 +420,10 @@ int bch2_replicas_gc_start(struct bch_fs *c, unsigned typemask)
int bch2_replicas_gc2(struct bch_fs *c)
{
struct bch_replicas_cpu new = { 0 };
unsigned i, nr;
unsigned nr;
int ret = 0;
bch2_journal_meta(&c->journal);
bch2_accounting_mem_gc(c);
retry:
nr = READ_ONCE(c->replicas.nr);
new.entry_size = READ_ONCE(c->replicas.entry_size);
@ -444,7 +444,7 @@ retry:
goto retry;
}
for (i = 0; i < c->replicas.nr; i++) {
for (unsigned i = 0; i < c->replicas.nr; i++) {
struct bch_replicas_entry_v1 *e =
cpu_replicas_entry(&c->replicas, i);
@ -454,10 +454,13 @@ retry:
memcpy(&k.replicas, e, replicas_entry_bytes(e));
u64 v = 0;
bch2_accounting_mem_read(c, disk_accounting_pos_to_bpos(&k), &v, 1);
struct bpos p = disk_accounting_pos_to_bpos(&k);
if (e->data_type == BCH_DATA_journal || v)
struct bch_accounting_mem *acc = &c->accounting;
bool kill = eytzinger0_find(acc->k.data, acc->k.nr, sizeof(acc->k.data[0]),
accounting_pos_cmp, &p) >= acc->k.nr;
if (e->data_type == BCH_DATA_journal || !kill)
memcpy(cpu_replicas_entry(&new, new.nr++),
e, new.entry_size);
}